It's not a redefinition, it's a reclassification.
We have a set of accounting rules that apply to firms who are middlemen with clearly distinct transactions with both their suppliers and customers. We have another set of accounting rules that apply to firms who act as a third party agent in a transaction.
Whenever you have such a classification, you are always going to have a gray area in between, firms where a judgement has to be made on which set of rules to apply.
Your unemployment example is great: we have 6 different definitions of unemployment, U1 through U6. Different ones should be used in different situations. And there are grey areas between the classifications -- are you a "discouraged worker" (u4) or "marginally attached worker" (u5)?
>Whenever you have such a classification, you are always going to have a gray area in between, firms where a judgement has to be made on which set of rules to apply.
Which is fine. It's okay to argue to have debates over whether we should be paying attention to U3 unemployment vs U4 or U5. What's not okay is to silently swap out the definitions just so you can get an attention grabbing title. It's bad if you're saying "the unemployment rate is actually 3x higher than what the government claims!", just as it's bad to put out a study saying "UnitedHealth's profit margins four times what it claimed"